Experimental Research On Remediation Of Contamination From Coal Wastes With SRB And Solid Wastes

Acid-mine drainage (AMD) that releases highly acidic, sulfate, and metals-rich drainage is a severe environmental problem, contaminating surface and groundwater as well as soils in coal mining districts in China. In this study, sulfate-reducing bacteria (SRB) were isolated from the loess polluted by AMD from gangue. Tests were conducted to investigate the mechanisms of heavy metals ions precipitation in the form of sulfides from gangue by SRB. The results show that sulfate-reducing bacteria can effectively immobilize sulfur and cadmium and zinc from coal waste. A series column leaching tests were conducted to evaluate the pollution of gangue remediated with SRB and solid wastes (sewage-sludge/fly ash). The results show that the leachates of the columns with Sewage-sludge and SRB present pH approximately 7.5, lower conductivity (<1.0 mS·cm-1). The AMD of the high iron concentration were remediated effectively, and excellent potential for treatment of dissolved metals that are commonly associated with coal waste piles, including Cd, Cr, Cu, Ni, Pb and Zn. A series pot inoculation tests show the SRB and cover of sewage-sludge possesses cooperative promotion of plant growth. Using SRB and cover of sewage-sludge cooperated with for gangue improvement is an effective way of ecological reconstruction in gangue piles area.